Roofing cover board, roofing panel composites, and method

Abstract

A roofing system includes a layer of insulation boards overlying a roof deck, and a layer of cover boards overlying the insulation boards. The insulation boards include a polyisocyanurate or polyurethane foam material that has a first density. The cover boards include a polyisocyanurate or polyurethane material that has a second density. The second density is greater than the first. The roofing system may also include a waterproofing membrane overlying the cover boards.

1. A roofing system, comprising:
 a layer of insulation boards overlying a roof deck, each insulation board comprising a polyisocyanurate or polyurethane foam material having a first density; 
 a layer of cover boards overlying the layer of insulation, each cover board comprising a polyisocyanurate or polyurethane material having a second density; 
 wherein the second density is greater than the first. 
 
     
     
       2. The roofing system of  claim 1 , further comprising the roof deck. 
     
     
       3. The roofing system of  claim 1 , further comprising a waterproofing membrane that overlies the layer cover boards. 
     
     
       4. The roofing system of  claim 1 , wherein the second density is between 6 lbs/ft 3  and 25 lbs/ft 3 . 
     
     
       5. The roofing system of  claim 1 , wherein the second density is between 4 lbs/ft 3  and 25 lbs/ft 3 . 
     
     
       6. The roofing system of  claim 1 , wherein the first density is less than 2.5 lbs/ft 3 . 
     
     
       7. The roofing system of  claim 1 , wherein the densities and thicknesses of the insulation and cover boards are selected to provide the cover boards with the compressive strength to resist deformation so that the cover boards are configured to protect the insulation boards. 
     
     
       8. The roofing system of  claim 1 , wherein each insulation board is bonded to one of the cover boards prior to installation to form a roofing panel composite. 
     
     
       9. The roofing system of  claim 1 , wherein each insulation board further comprises a facer overlying and bonded to a top major surface of the insulation board, the facer comprising a nonwoven mat. 
     
     
       10. The roofing system of  claim 1 , wherein each cover board further comprises a facer overlying and bonded to a top major surface of the cover board, the facer comprising a nonwoven mat. 
     
     
       11. The roofing system of  claim 1 , wherein each insulation board comprises a length and a width and a thickness. 
     
     
       12. The roofing system of  claim 11 , wherein the length and width are about 8 feet and 4 feet respectively. 
     
     
       13. The roofing system of  claim 11 , wherein the thickness is greater than about 0.5 inches. 
     
     
       14. The roofing system of  claim 1 , wherein each cover board comprises a length and a width and a thickness. 
     
     
       15. The roofing system of  claim 14 , wherein the length and width are about 8 feet and 4 feet respectively. 
     
     
       16. The roofing system of  claim 14 , wherein the thickness is between about 0.2 and about 0.4 inches. 
     
     
       17. The roofing system of  claim 1 , wherein each cover board further comprises a facer underlying and bonded to a bottom major surface of the cover board, the facer comprising a nonwoven mat. 
     
     
       18. The roofing system of  claim 17 , further comprising wind uplift reinforcement means interposed between the facer and the bottom major surface of each cover board to coincide with a fastener pattern for securing the insulation boards and cover boards to a roof deck. 
     
     
       19. The roofing system of  claim 17 , wherein the wind uplift reinforcement means comprises a plurality of scrim reinforcement patches or strips. 
     
     
       20. The roofing system of  claim 1 , wherein each insulation board further comprises a facer underlying and bonded to a bottom major surface of the insulation board, the facer comprising a nonwoven mat. 
     
     
       21. The roofing system of  claim 20 , further comprising wind uplift reinforcement means interposed between the facer and the bottom major surface of each insulation board to coincide with a fastener pattern for securing the insulation boards and cover boards to a roof deck. 
     
     
       22. The roofing system of  claim 21 , wherein the wind uplift reinforcement means comprises a plurality of scrim reinforcement patches or strips. 
     
     
       23. A method of roofing a building, the method comprising:
 providing a layer of insulation boards over a roof deck, the insulation boards comprising a polyisocyanurate or polyurethane foam material having a first density; 
 providing a layer of cover boards over the insulating layer, the cover boards comprising a polyisocyanurate or polyurethane material having a second density; 
 wherein the second density is greater than the first. 
 
     
     
       24. The method of roofing a building of  claim 23 , further comprising fastening the insulation boards and the cover boards to the roof deck. 
     
     
       25. The method of roofing a building of  claim 23 , further comprising providing a waterproofing membrane over and adhered to the cover boards. 
     
     
       26. The method of  claim 23 , wherein the second density is between 6 lbs/ft 3  and 25 lbs/ft 3 . 
     
     
       27. The method of  claim 23 , wherein the second density is between 4 lbs/ft 3  and 25 lbs/ft 3 . 
     
     
       28. The method of  claim 23 , wherein the first density is less than 2.5 lbs/ft 3 . 
     
     
       29. The method of  claim 23 , wherein the densities and thicknesses of the insulation and cover boards are selected to provide the cover boards with the compressive strength to resist deformation so that the cover boards are configured to protect the insulation boards. 
     
     
       30. The method of  claim 23 , wherein each insulation board is bonded to one cover board to form a roofing panel composite, and wherein the providing the insulating layer and providing the layer of cover boards are accomplished by providing the roofing panel composites.